In the scanning optical microscope a focused light spot is used to illuminate the object and some property monitored as the spot is scanned relative to the object to build up an image. By monitoring different properties it is thus possible to use the scanning optical microscope in a wide range of imaging modes, which can be used to give much information concerning the structure and properties of semiconductor materials and devices. In the optical-beam induced current method the focused light spot generates electronic carriers in a semiconductor specimen, and the resultant current monitored. The technique can be used to study defects in semiconducting materials and to measure electronic properties. If instead the reflected light is monitored we can obtain images in which resolution, contrast and depth of focus are all improved relative to conventional optical microscopy. Using the confocal imaging mode surface topography of thick structures can be investigated. In the scanning optical microscope we gain all these advantages whilst avoiding the disadvantageous effects of an electron beam and the necessity for a vacuum environment.
Sheppard, C. J. R.
"Scanning Optical Microscopy of Semiconductor Materials and Devices,"
Scanning Microscopy: Vol. 3
, Article 3.
Available at: https://digitalcommons.usu.edu/microscopy/vol3/iss1/3